Flexible tubular food casings of the type mentioned at the outset are known and copiously described. They are produced by coating a fibrous support material, in particular a textile support material. Coating is generally performed using aqueous dispersions. Frequently, in this process, acrylic dispersions are used Such casings having a textile support material and coated with acrylic dispersions are described, for example, in DE 37 04 563 C2, whose United States equivalent is U.S. Pat. No 5,246,750, and in DE 31 47 519, whose United States equivalent is U.S. Pat. No. 4,525,418. After coating, customarily, a drying step follows. In further processing steps, the coated support materials are finally processed by stitching, gluing, sealing, or in other customary ways, to form flexible tubular casings.
Cellulose fiber skins having a PVDC inner coating are also known (see, for example, EP 0 904 700 A1, whose United States equivalent is United States Patent Publication No 2001/0048986). The inner coating is produced using an aqueous dispersion of a vinylidene chloride copolymer. Cellulose fiber skins contain a reinforcement of a fiber paper, in particular a paper made of hemp fibers or abaca fibers. A drying step is necessarily associated with the coating.
Finally, flexible tubular textile skins are also known, on the full surface of the inside of which a film made of thermoplastic sealable or weldable plastic is applied in layer form or laminated (DE 10 2004 048 057 A1). The film can consist of polyester, polyamide, polyolefin or other thermoplastics. They can be stretched or unstretched. The connection between the film and the textile support material is not satisfactory in all cases, however, since the polymers of the film do not enclose the fibers.
The dispersions used in dispersion coating generally contain 50 to 60% by weight of solid, the remainder consists essentially of water. Therefore, during the drying, a considerable amount of water must be evaporated off. This is highly energy consuming and expensive. In addition, dryers having a great length are required therefor. As a result, a high space requirement for such a dispersion coating plant is required. In addition, for operating such a plant, a plurality of persons are required. The coating dispersions must be made up before coating according to a defined formula. For this purpose, personnel are also required. Likewise, owing to the dispersion batch and the drying, environmental pollution is caused.